Preheat oven to 400°F (200°C).
Mince the garlic, rosemary, and thyme, then combine in a small bowl with half of the olive oil, salt, and pepper.
Rub the herb mixture evenly over all sides of the beef sirloin roast.
Trim the Brussels sprouts and slice the carrots into half-inch thick coins.
Toss the vegetables with the remaining olive oil, salt, and pepper on a large parchment-lined sheet pan.
Place the beef in the center of the pan and surround it with the prepared vegetables in a single layer.
Roast for 20-25 minutes until the beef reaches an internal temperature of 135°F for medium-rare and the vegetables are tender and golden.
Let the beef rest for 5 minutes before slicing thinly against the grain to serve with the roasted vegetables.